A SEARCH FOR COLOR ENCODING IN RESPONSES OF A CLASS OF FLY INTERNEURONS

Extracellular recordings were obtained from single units in the lobula region of the optic lobe of the blowfly Calliphora phaenicia and housefly Musca domestica. These units responded selectively to the direction of movement of objects in the visual field. Previously it was suggested that these units are part of the neural system that controls flying behavior. The responses of these units were examined with monochromatic light flashes over four log units of intensity. No opponent" cells were found. The spectral sensitivity was determined directly and found to be similar for all units studied. Responses patterns were investigated with test flashes of equal physiological brightness. It was concluded that color is not encoded by this class of interneurons. It is suggested that the optomotor response is determined by the activities of retinula cells 1-6. © 1969 Springer-Verlag."